lib/console.c

   1 #include <stdint.h>
   2 #include <stdbool.h>
   3
   4 #include "console.h"
   5 #include "microwatt_soc.h"
   6 #include "io.h"
   7
   8 #define UART_FREQ 115200
   9
  10 /*
  11  * Core UART functions to implement for a port
  12  */
  13
  14 static uint64_t potato_uart_base;
  15
  16 static uint64_t potato_uart_reg_read(int offset)
  17 {
  18         return readq(potato_uart_base + offset);
  19 }
  20
  21 static void potato_uart_reg_write(int offset, uint64_t val)
  22 {
  23         writeq(val, potato_uart_base + offset);
  24 }
  25
  26 static int potato_uart_rx_empty(void)
  27 {
  28         uint64_t val;
  29
  30         val = potato_uart_reg_read(POTATO_CONSOLE_STATUS);
  31
  32         if (val & POTATO_CONSOLE_STATUS_RX_EMPTY)
  33                 return 1;
  34
  35         return 0;
  36 }
  37
  38 static int potato_uart_tx_full(void)
  39 {
  40         uint64_t val;
  41
  42         val = potato_uart_reg_read(POTATO_CONSOLE_STATUS);
  43
  44         if (val & POTATO_CONSOLE_STATUS_TX_FULL)
  45                 return 1;
  46
  47         return 0;
  48 }
  49
  50 static char potato_uart_read(void)
  51 {
  52         uint64_t val;
  53
  54         val = potato_uart_reg_read(POTATO_CONSOLE_RX);
  55
  56         return (char)(val & 0x000000ff);
  57 }
  58
  59 static void potato_uart_write(char c)
  60 {
  61         uint64_t val;
  62
  63         val = c;
  64
  65         potato_uart_reg_write(POTATO_CONSOLE_TX, val);
  66 }
  67
  68 static unsigned long potato_uart_divisor(unsigned long proc_freq, unsigned long uart_freq)
  69 {
  70         return proc_freq / (uart_freq * 16) - 1;
  71 }
  72
  73 void potato_uart_init(void)
  74 {
  75         uint64_t proc_freq;
  76
  77         potato_uart_base = UART_BASE;
  78         proc_freq = readq(SYSCON_BASE + SYS_REG_CLKINFO);
  79
  80         potato_uart_reg_write(POTATO_CONSOLE_CLOCK_DIV, potato_uart_divisor(proc_freq, UART_FREQ));
  81 }
  82
  83 void potato_uart_irq_en(void)
  84 {
  85         potato_uart_reg_write(POTATO_CONSOLE_IRQ_EN, 0xff);
  86 }
  87
  88 void potato_uart_irq_dis(void)
  89 {
  90         potato_uart_reg_write(POTATO_CONSOLE_IRQ_EN, 0x00);
  91 }
  92
  93 int getchar(void)
  94 {
  95         while (potato_uart_rx_empty())
  96                 /* Do nothing */ ;
  97
  98         return potato_uart_read();
  99 }
 100
 101 int putchar(int c)
 102 {
 103         while (potato_uart_tx_full())
 104                 /* Do Nothing */;
 105
 106         potato_uart_write(c);
 107         return c;
 108 }
 109
 110 int puts(const char *str)
 111 {
 112         unsigned int i;
 113
 114         for (i = 0; *str; i++) {
 115                 char c = *(str++);
 116                 if (c == 10)
 117                         putchar(13);
 118                 putchar(c);
 119         }
 120         return 0;
 121 }
 122
 123 #ifndef __USE_LIBC
 124 size_t strlen(const char *s)
 125 {
 126         size_t len = 0;
 127
 128         while (*s++)
 129                 len++;
 130
 131         return len;
 132 }
 133 #endif